Drafting of cotton and like fibers



' R. P. RICHARDSON i DRAFTING oF COTTON AND LIKE FIBERS pril 7, 1936.D

Filed Deo. 20. 1954 2 Sheets-Sheetr l April 7, 1936,. R P. RHCHADSN DRAFTING OE' COTTON AND LIKE FIBERS Filed Deo. 20. 1954 2 Sheets-Sheet 2 Patented Apr. 7, 1936 PATENT oFFlc-E DRAFTING F COTTON .ANDy LIKE FIBERS Ralph Pilshury Richardson, Bombay, British India Application December 2.0, 1934, Serial No. 758.497 In Great Britain April 24, 1933V 4 Claims.

My invention relates to improvements in the drafting of cotton and like staple fibers in the manufacture of yarn and thread.

One of the obJects of my invention is to obviate the extravagance of drafting eiort consequent upon the present day mode of drawing-frame doubling. In mill practice, a fixed draft roller setting interval obviously cannot selectv and draft fibers of greatly varying length in a positive manner. Much or' the necessary draft therefore has unavoidably to depend upon the chance movement of the fibers of shorter length. Doubling as commonly practiced, which involves combining a plurality or ordinary card slivers, usually six in number, is, apart from its being the source of productive power of the system, generally believed to possess the virtue of the-undesirable efl'ects of the present haphazard method of chance fiber drafting. I

Such doubling which involves presenting to the drafting rollers a relatively thick strand of fibers,

results in an overcrowding of the eifective nip of the rollers and thus less the fibers.

My invention is based upon a new and comprehensive conception of the doubling and drafting functions and involves presenting a minimum positive selectivity of number of fibers per unit roller nip length at each drafting stage. In consequence the drafting rollers are afforded the opportunity of directly selecting and withdrawing in a positive manner from the strand, at each draft zone, a greater number of fibers in any given interval of time than is at present possible in everyday standard practice.

.'Ihe invention will be readily understood from the following description in commotion with the accompanying drawings in which:

Figure 1 shows diagrammatically a layout or drafting system embodying the invention,

Figures 2, 3 and 4 are views of three guiding devices for use in the system shown in Figure 1 and, 1

Figure 5 is a perspective view of a suitable form of dorf er and coiler mechanism while Figure 6 shows the doffer employed.

Referring to Figure 1, I indicates the passage of the material through a revolving at carding engine, the full width doler web being divided into four part slivers of equal size and delivered at a. This is intended for the higher range of yarn comprises four rollers from ywhich the slivers emerge as a combined sliver as at c. 1f, however, the doler web had been divided into six part-slivers, twelve of such slivers would be combined in the drawing-frame 2. Where so desired, as for example, in the event of processing ner or alternatively better quality yarns, a second passage of drawing-frame may be utilized. In this case eight or, in the case of initial division into six part-slivers, twelve of the slivers c are now passed through the rollers of a second drawingframe 3 and combined into a single sliver designated e, three of which slivers are shown passing from f, through the rollers of a ily-frame or slubber 4 to be doubled into a single strand of rove y. The latter'step is repeated from h in a second fly-frame or rover 5 and three of the strands i produced are shown passing from :i through the rollers of a spinning frame t to be drafted and twisted into the single thread o; yarn at 1c.

The traversing guides 1, 8 and 9 shown in Figures 2, 3 and 4 are employedin conjunction with the fly-frames 4 and 5 an. the spinning frame 6, respectively, and serve to guide the strands through the rollers at the frames 4, 5 and t while giving maximum width of ribbon without any possible overlapping of the three unit strands at each stage.

Any suitable mechanism may be employed for the division of the doer web. For example, it will be apparent that d'olfer and coiler mechanism as are employed in the treatment of cotton waste may be utilized. One such known construction is shown in Figures 5 and 6.

The doier i0, which is more particularly shown n Figure e, is of the ordinary type and me nnet is also standard. The surface of the roller is however divided by leather bands of about inch width or more or less, into four parts of equal area. Of course the number of leather dividers employed depends upon the number of part-webs into which the card' is divided. Likewise the number of coiler and can mechanisms will also correspond to the number of part-slivers desired.

-In operation the eece is stripped by the comb `(not shown) in the standard way and is divided by the leather ybands I5 into four equal-size part webs covering the areas indicated by I4. Through the guides II the part-webs separately pass lto rollers to select a greater number of bres of correspondingly shorter length.

As has hereinbefore been pointed out the important feature of the present invention consists in presenting a minimum number of` flbers per unit roller nip length at each successive draft stage. Technologically the ideal conditions, for maximum fiber selectivity with my invention, would be attained if the fleece or strand at each stage were one ber thick and the fibers comprising the width of the fleece were lying parallel and closely side by side without any loss of rollerwidth and with no overlapping of the bers. But in commercial mill practice this ideal is not attainable because (1) one Width of carding engine has to serve a wide range of yarn counts, and (2) the number of fibers necessary to form any given count of yarn is, due to their varying quality, not necessarily the same in all cases.

For these reasons alone it is not practicable to prescribe for any given count of yarn or range of counts the number of part-slivers into which a given doffer web must be divided to give optimum result. For average practice in the case of the doifer web of a 37 inch carding engine, four equal size part-webs are employed for 70s counts of yarn and upwards. For counts of 30s to 70s a 40 inch card web is divided into iive equal partwebs and for counts below 36s a 45 inch doifer web is divided into six equal part-webs.

In the tables below set forth specific data is given to show one possible scheme of draft according to the invention in comparison with a typical example of the standard practice now in vogue for the production of yarn of the type of 40s count specified.

Standard practice f Carding engine Drawrame No. 1 Drawirame No. 2

0.15 henk card sliver 6 ends up, 6.2 draft, will contain approx- 0.155 hank drawimately 25,200 bers ing. These six sliver. These 6 in its cross section. slivers at back ocslivers occupy 4 cups:7 4", 4% at et back: 4% front.

T011 R{Back=37800. R{Back=36750. Front=5795. Front=5260.

M y system Carding engine Drawframe No. 1 Drawframe No. 2 v

0.16 bank card sliver 10 ends up, 7.2 draft, 10 ends up 7.8 draft d1v1ded into five 0.64 henk sliver 0.42 henk nished equal part slivers drawing. These sliver. These 10 equal 0.75 henk sliv- 10 slivers occupy slivers occupy 4% er or 5,040 bers in 4% at back and at back and 4% at cross section. 4% et front. front.

R Back=11200 R{Back15250 Front-1472 Front-1888 Standard practice Slubber Intermediate Rover Spinning 1 end up 4.0 2 ends up 4.7 2 ends u 5.7 1 end n 9.0 dran, 0.678 draft, 1.58 draft, p4.o dra! pnrs hank slubbank. These henk roving. counts 840 bing. This two slivers 4783 bers fibers conone sliver contain 11,200 contained in tained in contains 22,- bers in x55. Mo. 360 bers in R Beck=35840 Back-38264 R Back=l6800 M at back. Front=7648 Front-67m Front=l880 Bck=29813 l {Front=7440 6 ends up, 6.5 draft` 0.169 henk finished,

The value R given in the above tables relates to one specific example only and is by way of illustration. R. is represented by the number of fibers per inch of length of roller nip or width of. eeoe employed. This eece Width is governed by the effective width of the strand guides employed (e. g., as in Figs. 2, 3 and 4) acting in conjunction with the top roller loading weights used to compress the fleece. The thickness of the fleece at each stage may be represented by the number of bers which compose the fleece thickness. The quality of the particular cotton mentioned above is such that it requires 1666 such fibers lying parallel and closely side by side without overlapping to form a fleece one inch wide and one ber thick, so that the thickness of the first drawing frame fleece shown with the present invention in the above table is approximately 6% fibers at presentation and .9 ber thick at the emergent fleece. (The corresponding figures with the standard system shown are 22.7 and 3.5 fibers, respectively.) l

In general mill practice, this fleece widththickness relationship will unavoidably fluctuate greatly. But whereas the width of the fleece will be controlled within relatively narrow limits, the thickness of the iieece will vary greatly, depending upon the carding engine-cum-yarn count range relationship, the number of drafting stages and the amount of draft employed at each stage, the width of the eece and tne number of bers contained in the iieece. It should be mentioned that 0.15 hank sliver represents the safe maximum limit of output of good quality sliver for 40s counts from a 40 inch carding engine with a 26 inch doffer running at 14 revolutions per minute. 'I'he formula employed for the calculation of the ber number is Cotton quality Yarn quality Average ber lengtl1-1.0lnch- Yarn counts.-40e. Average ber weight-0.14 x 10'o Lea strength in1bs.-40.

ounce. Average ber strength-0.14 ounce.

Average ber (ribbon) width-0.6

x10*t inch.

Turns per inch-25.3 or 40's coun Front roller speed dla., 140

revs. per mm.

The foregoing detailed description has been given for clearness of understanding only and no unnecessary limitation should be understood therefrom. For example the invention is applicable to all counts of carded and combed yarns.

aoaassc Again the draft stages may vary with, for example', the quality of yarn to be produced. In

the lcase of a good quality 20s yarn the following scheme may be adaptedz-starting with a hank of card sliver of. 0.17, the drafts at the frames 2 and 3 (Figure 1) are 7.4 and 8.0 respectively followed by a slubber draft as at 4 of 9.0 vwith a nal draft of 24 in the spinning machine as at 6.

li claim:-

ll. A process of drafting cotton and like staple bers which comprises dividing the full-width doer web of a cotton revolving iiat carding engine into from four to six equal size part-webs, according to the width of the doier and the type of yarn required, combining the part-slivers from two such doifer webs by passage through drafting rollers of a drawing frame, so that the number of bers per inchof. width of the web on said rollers will be maintained at a low valuecomparedto standard practice, feeding three separately guided combined slivers from the drawing frame through a ily-frame to form a strand of rove and separately guiding three of such fine rovings produced to a final spinning frame, wherein said rovings are combined and twisted into the final strand of yarn.

2. A process of drafting cotton and like staple ibers which comprises dividing the full-width doffer web of a cotton revolving flat carding engine into from four to six equal size part-webs, according to the width of the doifer and the type of yarn required, combining the part-slivers from two such doffer webs by passage through drafting rollers of a drawing frame, so that the number of bers per inch of width of the web on said rollers will be maintained at a low value compared to standard practice, feeding three such combined slivers from the drawing frame through a fly-frame to form a strand of rove, passing three such strands of. rove through a second fly-frame, and combining three of such fine rovings produced in a nal spinning frame, wherein said low value compared to standard practice, passing i such a number of combined slivers through a second drawing frame delivery, feeding three separately guided combined slivers produced through a ily-frame to form a strand of`rove, passing three. separately guided rovings through a second fly-frame, and separately guiding three of such fine rovings produced to a iinal spinning frame, wherein said rovings are combined and twisted into the nal strand of yarn.

4. A process of drafting cotton and like staple fibers which comprises dividing the full-width doffer web of a cotton revolving flat carding engine into from fourto six equal size part-webs, according to the width of the doifer and the type of yarn required, combining a number of such part-webs equivalent to two such doiier webs by passage through a delivery of a drawing frame, so that the number of fibers per inch of width of the web on said rollerswill be maintained at a low value compared to standard practice, passing such a number of. combined slivers through a second drawing frame delivery, feeding three such vcombined slivers produced through a y-frame combined and twisted into the final strand of yarn.

RALPH PILSBURY RICHARDSON. 

